Grand Designs cliff-hanger creates prototype for steep sites

COLLEEN HAWKES

Last updated 10:14, November 2 2015

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Steel cables and rock anchors secure this multi-level Wellington house to the cliff, so it appears to float above the bush.

Hidden away in the bush-clad hills and valleys are hundreds of building sites within a couple of kilometres of the Wellington CBD. But despite their magnificent views and close proximity to the city, these sites are constantly bypassed by potential buyers, for one simple reason - they're too steep.

For architect Nic Ballara, this was no drawback. Determined to build a spectacular home for his wife Callie and daughter Mila, Ballara came up with a design for a house that would literally hang off a 45-degree cliff face.

His project, known as the gravity-defying house, was filmed for Grand Designs New Zealand.

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Architect-owner Nic Ballara, wife Callie and daughter Mila say the site's magnificent views and close proximity to the CBD were key attractions.

Right from the outset, Ballara says he wanted to create something special. "As an architect I see a lot of cut-and-paste projects, where ideas are gathered from here and there and pulled together. That's not architecture. I wanted to try something different, and in doing so create a prototype for Wellington. I wanted to prove it is possible to turn an inhospitable site into a building site."

The architect believes Wellington's sprawl of subdivisions is not the answer to the housing crisis. "There are other, more clever solutions, such as building more densely and utilising steep sites. Wellington's topography ensures houses on these sites are not overlooked by neighbours. You can be so close to the city yet feel right in the middle of nowhere."

Ballara's own design turns structural engineering on its side, literally. The house is supported at the rear by a "backpack" of rock anchors and steel cables, rather than traditional foundations beneath the house, which means it cantilevers out from the cliff, right beside the bush.

Grand Designs guru architect Chris Moller says most people would be astonished to think a house could possibly be built in this position – workers on the site frequently used the words "brave", "crazy" and "nuts".

"The site is almost not there at all, but this is not unusual for Wellington."

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One entire wall of the house is glazed, affording a spectacular close-up view of the bush.

Moller himself lives on the opposite side of the city, on a site that is equally steep – his house is reached by 200 steps up a zigzag path on a 45- to 50-degree slope, and he doesn't have a cable car.

"This project is particularly unique, however," he says. "Nic has developed a genuine prototype informed by the challenge of the site. He has come up with a really strong conceptual idea whereby the house floats off the side of the hill. It is always good to question the generic way building designs are approached, and what he has done is extraordinary."

Not surprisingly, the build was not without its challenges. "The building of the house was a big learning curve," says Ballara. "The building team, project manager Phil Stewart and myself were inventing things as we went along."

Moller puts it a little more bluntly. "There were a lot of creative thinkers and risk takers on hand to make sure it didn't slide down the hill."

There are other ways the house challenges perceived conventions. "It's the rooms on the lowest level that feel like they're the highest above ground," says Ballara. "This is because the cantilever is most obvious at this level. There are also other interesting plays in the way you experience the house. Instead of a traditional hallway creating a spine, we have a vertical corridor, in the form of the glass lift at the rear."

The house provides close connections with the landscape and key structural elements. A huge steel cable, supported by a rock anchor, travels diagonally across the house. And throughout the house heavy materials and exposed mechanical elements sit alongside floating balustrades and invisible walls.

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Natural light and white walls enhance the light, spacious look of the interior.

"Mesh walls continue the language of the hanging house, reminding us that we are effectively abseiling off a cliff," says Moller. "The house feels both securely anchored and suspended in space."

Moller says a daring project such as this highlights a need to change the system that puts roadblocks in the way of design innovation. As with many of the Grand Designs projects, there were extensive delays with consents. "The time and cost impact of these delays are always taken on board by each of the clients. Ideally, it would be great to see diversity encouraged, with a top-down structure established that is much leaner and more supportive."